I have more than 2500 songs in the song folder I use. They are all on the laptop, just lyrics with chord changes. They are also on my keyboard. I probably could do a thousand of them without looking at words, not sure. When you play four hours a night, five or six nights a week, and for many of the same people, you have to keep it fresh. 30 songs won't do it.
One great thing about having them on the arranger, is that the audience can't tell you are looking at them. Most of the time all I have to do is glance at the words occasionally anyway.
One of the things I did right over the years is to write down the words and chords of EVERY song I've learned. At first I typed them, and accumulated hundreds, soon filling up several loose-leaf binders. When computers came along, I re-typed every one into a word processor.
For the past 25 or 30 years I've done them all that way.
In the past, you had to record the song, listen to it, write down the words, get a guitar or keyboard and play along with so you could figure out the chords, the key you want to do it in, etc. By the time you did all this you had pretty much learned the song.
Now it's much easier. Just pull it up on YouTube, Google the chords and lyrics, copy and paste, to make a chart, find a suitable style and go. Of course you have to make sure the words and chords are correct. Now I usually also enter the new song into the arranger as a Songbook or Registration entry. Then press one button and everything is ready to go.
To make a suitable repertoire is not a quick and easy thing.
I think it would be much easier if a person specialized in one genre, say Jazz, or Classic Rock, or Standards, or Blues or Country. I have to some of all of it.
Don't know if this is encouraging, but I hope it helps.